Perpendicular
by AstralVortex
Summary: After Kazuichi builds a dimensional portal, Junko interferes and forcibly sends Makoto through. Now, Makoto must travel through several parallel worlds in order to find a way back home and stop Junko's master plan, whatever that may be.
1. Chapter 1

**Chapter 1: Prologue**

* * *

Makoto and Sayaka walked side-by-side after finishing up a calculus test and on their way back to the dorms.

"What'd you get on number sixteen?" Makoto asked.

"C"

"Oh… I picked D."

"I mean, the phrasing of that was awkward. By 'Coat Sales' did it mean the amount of coats sold or the profits from selling it?" Sayaka replied. "Oh, that reminds me, I left one of my coats up in the physics lab! Can you go get it for me?"

"I'm willing to do so and all… but is there a reason you can't run up there yourself?"

"I have to rush to a recital. We're doing a performance on Friday afternoon and my group can't start without me, and I already have to get ready, like, now"

"Sure."

"I'll be in my room," Sayaka replied.

Makoto left Sayaka's side and ran up the stairs to get to the physics lab. Gripping the handle, he flung open the door to the physics lab.

"AAAAAHHHH!" a scream came. It took Makoto a few seconds to realize that there was someone who he just slammed the door into. "What gives?"

"You're… Kazuichi, right?"

"Huh?" Kazuichi asked, rubbing the back of his neck. "Erm, yeah."

"Sorry," Makoto said. He ran into the room and began looking around for the coat.

"What are you looking for?"

"One of my friends left a coat up here," Makoto replied. "Have you seen it?"

"Oh… a coat…" Kazuichi said. "Well, you can give up."

"Huh? Why?"

"I made something… it's… just come with me."

Kazuichi told Makoto to come with him as they entered the repository behind the physics lab. There, there was a machine. The center of it was a giant, person-sized loop with a diamond-shaped crystal on the very top. The sides were shaped like wings but also had a base that was flat so that the loop could stand upright.

"What is this?" Makoto asked.

"To be honest, I'm not really sure."

"You built this, right? You don't know what you built?" Makoto facepalmed.

"Well, someone left me a blueprint while I was busy making some Minimarus."

"Minimarus?"

"Don't worry about it. Not important. But I saw the blueprint, and it wasn't labeled or anything. So I decided to build it. And it seemed like the person wanted me to build it, as they left the crystal on top of the blueprint. You know, the one on the top of the machine?"

"What does this have to do with the coat? I bet Sayaka's waiting for me."

"Well, it seems like it opens some kind of field. I found that coat and figured someone abandoned it, y'know? So, I decided to throw it through to see if it would come out the other side, and what would happen to it."

"Let me guess," Makoto said. "You threw it through and ash came out the other side."

"No, not really," Kazuichi replied. "I threw it through, and nothing came out."

"Hmm… that's weird…" Makoto replied. He pulled out his phone and dialed Sayaka.

"Makoto! Have you found it?"

"Yeah, no, it's a long story. You should probably just get going. I'll talk to you more tomorrow."

Sayaka sighed through the phone. "Alright."

Makoto hung up as he turned back to Kazuichi. "Let me get this straight. A mysterious person who you didn't see or notice gave you a mystery blueprint that you didn't even know what it did or how dangerous it could be and you thought it would be a good idea to build it and throw in something that didn't even belong to you."

"Erm.. yeah."

"Oy vey, Soda. Oy vey. Just… can you let me see it?"

"Sure," Kazuichi replied. He flicked a lever as the loop began to glow, with the space in the middle transforming into a sheet of bright light.

"Turn it off, turn it off!" Makoto said, shielding the light from his eyes. Kazuichi flicked it closed. "What the hell was that?"

"You'll learn about it soon," a feminine voice said. Makoto and Kazuichi looked behind them to see a head with two strawberry blonde pigtails.

"Junko?" Makoto asked. "A-Are you the one who gave Kazuichi the blueprints?"

"Yup," Junko replied.

"Why?" Kazuichi asked. "I mean, our classes don't even interact, and why would a fashion diva like you have that blueprint?"

"Even if I told you, you wouldn't remember." Junko said, pulling out a syringe.

"What is t-"

Kazuichi didn't have a chance to finish his sentence as Junko darted in and stabbed the syringe into Kazuichi's neck as he collapsed.

"W-what was t-" Kazuichi muttered.

"It's a type of anesthetic. You'll fall unconscious and lose the last hour or so of your memory."

Kazuichi's eyes fell closed.

"What?" Makoto asked, turning to Junko. "What is this? What are you doing to him?"

"It's far better than what I'm doing to you."

After hearing those words, Makoto darted to the door and flung it open to the physics lab. But before he could move any further, Junko grabbed his arms and pricked him with a second syringe.

"Don't worry," Junko said. "This will just temporarily paralyze you for around five minutes."

Makoto's limbs went limp as he clunked to the floor. He tried to speak, but his lips wouldn't let him. His eyes darted around, trying to make sense of the situation.

"I'll explain everything to you eventually, if you make it, that is. But by then, it'll be too late to stop me."

Junko dragged Makoto's limp body to the machine and flicked it on.

"See you on the other end."

Junko chucked Makoto into the bright light. She then turned the machine off.

"We'll miss you, Makoto. Come back soon." she sarcastically said. For the last measure, Junko reached up and plucked the crystal out of the top of the machine before tossing it around in her hands and leaving.

* * *

White. All white. That was all Makoto saw. But what he felt was much scarier. He was falling. Just falling.

How long was he falling for? How far was he falling? But he knew those questions wouldn't matter. He knew that after this amount of time, he was going to die the moment he hit the ground, if there even was one.

The white morphed into grey, and then black.

"_This is it, huh?" _Makoto asked himself. "_Wasting away in a black void…" _

It was then that he noticed there was something beneath him. Some kind of flooring. And underneath him? Some kind of cloth or fabric. But that didn't make any sense. Wasn't he just falling?

The anesthetic seemed to still be in effect. He couldn't move his legs, he couldn't speak, and he couldn't open his eyes.

Well… he wasn't dead at least. Waiting a few moments for the anesthetic to wear off, he eventually managed to open his eyes and push himself off the ground.

"T-the repository?" Makoto asked. "The machine's not here? Junko? Kazuichi?"

No response. He was alone.

"I... I'm confused. I need a rest."

He exited the repository, unaware of what was in store for him.

* * *

**This chapter serves as me 'testing the waters', as in testing the response to the story idea in general. Don't be offput by the length, I plan for the rest of the chapters to be 4-5k words long. Please follow, favorite, kudos, and leave a review if you're interested in ****seeing more. **


	2. Chapter 2

**Chapter 2: The Mirror World**

* * *

Standing in the repository, Makoto was disoriented. Everything seemed normal. Junko probably just gave him something hallucinogenic. That was it.

But once he left into the physics lab, he realized… no. Everything was not normal.

"Why… Why is everything backwards?"

Normally, the air purifier in the lab was so cluttered that you could only walk around it to the left (while viewing from the repository). But now, the pathway was to the right.

Makoto turned around and checked the repository. When he woke up, the lights were turned off. But as he reached for the light switch, he noticed there wasn't one.

"Huh?" he asked. He felt around on the other side, and there it was. The lights flickered on to reveal a completely mirrored repository.

"What is this?" Makoto asked. But something caught his eye. A grey coat, lying on the ground. He walked over to pick it up.

"This is Sayaka's… what's going on here?"

He just shook the feeling and hung the coat around his arm before running out of the lab. Hiro must've spiked his food with drugs or something.

He ran out to the hallway to see that it, as well, was mirrored. What the hell?

"I really need to get more sleep."

He found the stairwell and descended down it, but bumped into someone before tumbling down to the bottom.

"Watch it, asshole!" a voice said. Makoto pushed himself back up to the ground.

"S-Sayaka?" Makoto asked, looking down at the idol. "What are you doing here?"

"What are you talking about?" she asked, face full of anger. "I go to school here."

"Weren't you supposed to be performing?"

"Performing? Why would I be performing? I came to Hope's Peak to get away from that whole mess. Wow, you're really dragging down the Naegi family name. I wonder what your parents would think of you."

Makoto was revolted by the assault-ish comments coming out of Sayaka's mouth. "Are you okay?"

"I should be asking you the same question. Why are you dressed so casually? It makes you look like a homeless person."

"Okay… I think you should have some time alone." Makoto said, holding his hands up. "This is yours."

Makoto tossed Sayaka her coat.

"Where did you get this?"

"You told me to go get it from the physics lab…"

"I literally just put it in my drawer. Were you snooping around in my room? Perv!"

"Okay, I'm too exhausted for this right now. I'm just going to go back to my room."

Sayaka glared at him before carrying on. What was that about?

Makoto shook his head and continued making his way back to the dorm, but not before he was stopped by Celeste… only she wasn't wearing her pigtails and had on a less… gothic outfit. She was still wearing a black suit with a white undershirt, but it was much less frilly and seemed more professional. The skirt was more plain and less wide. Sure, it looked very gambler-y but was nowhere near what he was used to seeing her in.

"Uhh… yeah?" Makoto asked.

"What's with the clothing of yours?" she asked, in a perfectly normal Japanese accent.

"Why does everyone keep asking me that?" Makoto asked, fed up. "What's with your outfit? And your voice?"

"What are you talking about? What about my voice?"

"You know what? I'll ask you later, Celeste."

"It's Taeko. Who's Celeste?"

"...I-I jus-... see you later."

Makoto left her behind as he continued walking to his dorm, shaking his head. What was happening?

Though the entire layout of the building seemed to him to be mirrored, at least his nameplate read from right to left.

He pulled out his key from his pocket and put it into the doorknob as it clicked and turned.

"I don't know why I thought that wasn't going to work," Makoto said under his breath. He entered his room, flicked off the lights and ran straight to the bed. Hopefully that would resolve his pounding headache and confusion.

* * *

*BEEP BEEP*

Makoto slapped his alarm clock as he groaned and got up. It was Saturday… but he didn't remember setting his alarm at 6:00 on a Saturday. Well… whatever. Hopefully more things would make sense now that his mind was cleared.

He was wrong. After turning on the lights and glancing around the room, he also noticed that this room was also mirrored, and there were several pieces of equipment around his room that he definitely didn't put there. Things like spray bottles, glass bottles filled with powder, some massive machine that he didn't recognize.

He cautiously walked outside and poked his head at the nameplate. Sure enough, the dorm nameplate displayed his name. Sighing in defeat, he went back into his room and looked at the stuff. Who put this here?

After freshening up and getting ready, he opened his drawer only to find suits and other things that would not be comfortable for him.

"What the hell?" Someone definitely put their stuff in his room.

Shutting the door, he figured that he would just ask the other students during breakfast and, if no one fessed up, he'd just go to the security guards at the data center.

But breakfast was a total clusterfuck that reduced his understanding even more. The first person to come into the dining hall was Hiro.

"Makoto? Why are you dressed like that?"

"I don't understand…" Makoto replied, resisting the urge to bang his head into the table.

"It doesn't matter," Hiro said. "How'd the case go?"

"Case?" Makoto asked. "What case?"

"Didn't you tell me yesterday that you were going to pull an all-nighter over some underground drug ring?"

"N-no?"

Makoto took a drink of his orange juice before digging into the pancakes that he had made earlier.

"Avoiding your caffeine, I see?"

"Eh?"

"Don't you normally drink coffee in the morning?"

"Uhh… no? I hate coffee. You should know this."

"..."

"Why are you looking at me like that?" Makoto asked, sliding backwards to try and escape the situation.

"You've been acting strangely."

"You're one to talk. What, are you going to say that I was abducted by aliens or something?"

"What kind of idiot do you think I am?"

"Do I have to answer that question?"

The two ate in silence as Mondo came in.

"Woah! Makoto, why are you dressed so casually?"

"That question again?" Makoto asked, groaning.

"Looks nice on you."

"Uhh… thanks?"

Slowly but surely, Sakura, Sayaka, Hifumi, Leon, Celeste, Chihiro, and Mukuro had all shown up. Each of them had made some sort of comment about him either about his clothes or the "case", whatever that was.

But nothing confused him more than when Byakuya and Toko came in. As expected, they came in together, but their conversation was far from usual.

"Go away," Toko said.

"If you say so," Byakuya replied.

"This is the sixth time you've asked this week. I don't like to date rich people."

"I could lose my money! I could lose the entire company! Everything for you, mistress!"

"Why don't you go lose your life?"

Makoto slammed his hands on the table. This was enough. "What the shit is going on here?"

"Hey, Koto, adjust your language!" Mondo shouted.

"No! I just come back one day, everything's fucking backwards, everyone here acts like they're on drugs, I have no idea what everyone's talking about, Toko's telling Byakuya to go kill himself, someone's been putting stuff in my room, and I'm just so pissed off right now!"

"Shut your mouth before I do it for you." Chihiro said.

"See! Behavior like that!" Makoto shouted, pointing at Chihiro.

"I'm not apologizing. I'm not."

"I think you need to calm down. You're probably just worked up." Leon said.

"Calm down? You expect me to calm down?"

"What's happening?" a new voice said. Kyoko! There's no way that she'd succumb to whatever prank this was.

"Kyoko, wha-"

He looked up to see Kyoko wearing a sweatshirt, jeans, and a baseball cap.

"Makoto?" Kyoko asked. "Weren't you just in the main ha- What's with th-"

"Is this entire class just mad?" Makoto asked, clenching his fists over his head.

Just then, Junko walked in. Makoto rolled his eyes as his vision went red. He stood up, pushed past Kyoko and Chihiro, and grabbed Junko by the collar to push her into the wall.

"OH MY GOD!" Mondo shouted.

"What the shit?" Taka asked.

Makoto slammed Junko's back against the wall. "What the hell did you do?"

"What are you talking about?" Junko replied. "Do what?"

"The machine, with Kazuichi, and the syringe…"

"You've lost me, but that sounds interesting. Do tell."

Makoto dropped her to the ground before he recoiled into his chair and put his hands between his heads. "Nothing makes sense."

"He's scaring me," Sakura said.

"Stop right there." a voice came from the entrance. Heads turned, but Makoto couldn't see who it was as everyone was blocking him.

"W-what?" Hiro asked, tremoring.

"This doesn't make any sense!" Kyoko exclaimed.

Heads went from Makoto to the mystery visitor.

"Pin him down!" Toko shouted. Before Makoto could stand up, Taka and Sakura grabbed his arms and bound him to the chair.

"There's… t-two of them?" Byakuya asked, staring at him.

The rest of the students cleared, creating a pathway from Makoto to the mystery visitor. As he approached, all Makoto could make out was the ascot cap and the suit he was wearing. But as he approached Makoto, his face came into view.

It was Makoto's. Makoto's face, Makoto's hairstyle, Makoto's voice.

"I don't know who you are, or why you're impersonating me," Other Makoto said. "But as a detective, I'm not letting this go unnoticed."

All of a sudden, Taka karate-chopped him in the neck as Makoto fell unconscious.

"Dude." Detective Makoto scolded.

"I couldn't help myself." Taka replied.

* * *

Makoto woke up in the nurse's office. Attempting to stand up, he realized that he was tied down to the posts.

"I wouldn't struggle if I were you," a voice said, one that sounded exactly the same as Makoto's. He adjusted his eyes to see his doppelganger.

"Who are you?" Makoto asked.

"The real question is who are you."

Makoto struggled in his ropes, trying to get free but to no avail. "Why am I tied down?"

"Why don't you answer my questions? Who are you?"

"I… I'm Makoto Naegi."

"Fine. If you're going to play this game, so be it. What's the rest of your story?"

"I… what do you mean?"

"What reason did you have to impersonate me and infiltrate this school?"

Makoto blinked and stared at the man looming over him. "I-Impersonate _you_? You're the one who just waltzed in with my face!"

Other Makoto stared. "I have the Ultimate Nurse working on a sample of your blood, so we'll work out who you are soon enough. It's in your best interest that you answer my questions, or else we might have to lock you up for longer than need be."

Makoto was silent. What was he supposed to say? He didn't know what was going on either.

Other Makoto reached for a cup and took a sip as the scent of coffee wafted in front of Makoto. "Why are you impersonating me? What reason do you have?"

Makoto wrinkled his nose at the scent of bitter coffee. "I know you're confused, but I'm confused too. I don't know what's going on anymore. Everything was normal until last night."

"Tell me."

"Well," Makoto said, sighing. "Sayaka told me to go fetch her coat upstairs in the physics lab. There, I met Kazuichi, an upperclassman, who showed me some machine that he built that seemed to make some sort of portal. Then, Junko drugged both of us and sent me through the machin…"

Makoto stopped and listened to his words again. "I… I probably just fell asleep."

"That does sound bizarre..." Other Makoto replied. But before he could finish, Mikan began running into the Nurse's office.

"M-Mikan, right?" Makoto asked.

"Yeah." she replied. "I did the analysis. His DNA matches yours. Perfectly. As if you were twins."

Other Makoto stared at him. "What?"

"Chances are, you're twins." Mikan replied.

"No!" Makoto replied. "I don't have a twin brother!"

"Did you grow up with your biological parents?" Other Makoto asked.

"Yeah. My mother Yui, father Haruto, and sister Komaru."

"Uhh…" Other Makoto replied. "That's the name of my family."

Other Makoto turned to Mikan. "You're sure this is correct, right?"

"Of course! I'm the Ultimate Nurse! Someone like me wouldn't mess up!"

"Can you just untie me?" Makoto asked.

"No."

The Other Makoto took a long, slow sip of his coffee while eyeballing Makoto.

"..."

"..."

"..."

Just then, the door burst open to reveal Hiro.

"What? Can't you see I'm in the middle of an interrogation?" Other Makoto replied.

"Yeah, but I have some big news!"

"Make it quick. I don't have all day."

"I just did some fortune telling, and it says that this Makoto's from another dimension!"

"..."

"What?" Hiro asked. "That's what I got!"

"I know your fortunes are supposed to be right seventy percent of the time, but that's just absurd. Stop wasting my time. I thought you were one of the smartest people here. Way to prove me wrong."

"T-That makes sense," Makoto stammered.

"Going on this little charade, are you?" Other Makoto replied. "Just give up already and tell me the truth."

"It does line up with my story. About the machine and why everything's like this-"

Other Makoto took a second to think. "To be fair… it does…"

"I've studied some physics and philosophy, and I think I know the basic theory"

"That is so weird coming from your mouth." Makoto said.

"Go on," Other Makoto replied, grabbing a chair to sit down.

"Hang on, I think everyone else should hear this." Hiro replied, running out of the nurse's office to round up the rest of their classmates.

* * *

Eventually, nearly the entire class besides Junko and Hina surrounded Makoto and Hiro in the nurse's office.

"Can you untie me now?" Makoto asked.

"No," Other Makoto replied. "Now, tell us the theory."

"Yeah, I don't appreciate my time being wasted," Toko said.

"Well, I have a friend who's a physicist and we've talked about this before," Hiro said. "Let's imagine that this universe is one of many. These universes are all different in their own ways. One of them might be suffering a zombie apocalypse, one of them might be in the middle of a warzone… but these are all alternate versions of the same universe. Now, if we imagine that _our _universe is a single line, we can take other universes and line them up in parallel to our universe. If we continue to do that, we may end up with a tube-like shape. Now what I think is happening to Makoto is that he's travelling perpendicularly. Like some portal or wormhole opened up connecting our world to his. Think of it like the rungs of a ladder, two parallel sticks being connected with perpendicular lines."

"Alright, so who is this then?" Kyoko asked.

"Well, it's a version of Makoto from an alternate universe," Hiro replied. "From a universe where he's seemingly not a detective and judging by his behavior, all of us act differently."

"That is kinda unbelievable," Mondo said. "But you are the smartest person in our class, so I believe you."

"Okay, I get it," Makoto replied. "Can you untie me? I'm really uncomfortable."

"No." Other Makoto said. "Is he dangerous at all?"

"We can't be sure yet," Hiro said.

"I'm not dangerous!" Makoto replied.

"Woah, so you're saying that we have alternate selves too," Toko said.

"Yeah, that's how the theory goes."

Everyone except Detective Makoto crowded around Makoto.

"What am I like?"

"Ooh! Tell me! Me next!"

"Shut up! Shut up!" Makoto shouted. "Look, I just want to get home."

"Well, if you want to get home, you're going to have to wait a bit," Hiro said. "My friend has all the details about parallel worlds and stuff, but he's studying abroad in Canada. I'll contact him so he can come back and help you, but it'll take at least a few days to come back here as well as work out what your problem is. It'll probably be best if you were to settle in."

"Wow, you have friends?"

"What's that supposed to mean?"

Makoto collapsed against his bed. "Nevermind… but can you untie me now?"

"Not quite yet."

"Oh, come on!" Makoto shouted.

"One condition. Just to make sure you're not a threat, we need to make sure you're supervised at all times. I'm not entirely convinced Hiro's theory is correct."

"Fine." Other Makoto replied. He undid Makoto's ropes as he flexed his wrists and ankles.

"That's a real theory, though, right?" Makoto asked. "I mean, it seems pretty outlandish."

"Yeah, but it's all we have to go off of now." Other Makoto replied. "Most of Hiro's fortunes seem pretty outlandish, but turn out to be true. Once he predicted that a group of sentient robots would attack everyone, and the next week, Sonia from Class 77 used Kazuichi's computer and accidentally downloaded a virus and it infected all of his robots. That did not turn out well."

"Anyways," Chihiro said. "Tell us what we're like."

"Hold on, I want to know what you guys are like. I'm the one who's going to be stuck here for a few days." Makoto said. "First off… You. Or… me? I guess?"

"What is it?" Other Makoto asked.

"Well, you don't seem like the Lucky Student here. And judging by how Kyoko's dressed, I'm guessing you swapped talents and you're the detective, right?"

"Yes. I'm Makoto Naegi, the Ultimate Detective. My entire family comes from a long line of detectives. My parents, my sister, we're all detectives." Detective Makoto replied. "But Kyoko being a detective? That's something I would pay to see."

Kyoko smiled and giggled.

"That is so awkward," Makoto said. "Second off, where's Hina? I haven't seen her all day."

"Hina?" Celeste asked. "Do you mean Asahina? Aoi Asahina?"

"Yeah… does she go by Hina here?"

Everyone shook her head.

"She's probably locked herself in her room." Sayaka said. "Little wimp."

"Oh… alright…" Makoto replied, trying to think. "It… It seems like everyone's defining trait has just kinda swapped from my dimension. In my dimension, Toko was the one who was always going after Byakuya…"

"What?" A few more gasps and laughs came from the back. "That's something I want to see! That'd be hilarious!"

Byakuya crossed his arms. "A world where Toko likes me?"

Makoto continued telling his story as the night went on.

* * *

**I've had this chapter done for like a week. IDK why it took so long for me to publish it. Anyways, time to answer some of the review questions that I got (on FFN. If you're on AO3 I'll reply to those questions directly. I also won't probably reply to anything that isn't really reply-able, but thank you for reading!)**

Guest asks: Will this personality change or physical change change through this makoto trip?

Answer: Erm... grammar. I'm not entirely sure what you're trying to say, but I'll try my best to answer. Makoto's body will not, like, magically change through this trip, and his personality will stay the same. However, he will always have a counterpart in which his body and personality CAN be drastically different.

doomqwer asks: how the world he jumps into effects like say he drops into a world like fairy tail does his body change according to the rules of the world and gain some type of magic or does he stay an average joe

Answer: His physical body will not change (like mentioned above), and I do not plan to drop Makoto into the universe of any other fandoms, just alternate versions of the DR universe. As for the magic you asked, I'm not entirely sure yet. I do plan to have some kind of magic dimension coming up in the future, but I'm on the fence about whether or not to let _our_ Makoto be able to use magic. If so, I'll make it so he has to learn it as it won't be something he'll be able to do from the start, but he probably won't be able to use it in worlds after it. If not, he'll have to just work with other people who can use magic.

jazzrapper asks: i also wanted to ask whether each chapter will be its own world or will there be a couple of chapters devoted to each world?

Answer: There will be a few chapters devoted to each world, I'm thinking maybe around 5 (Introduction to the world, character interaction/filler, plot development, character interaction/filler, leaving the world), but depending on how motivated I am it might be a little shorter.

Red asks: will this be like an isekai? and you know what worlds will makoto go to?

Answer: I don't know what an isekai is. After looking it up, I still don't know. So my answer is Pikachu. Anyways, I do know a few of the worlds. I don't know the exact amount I will make but it definitely will be less than 6. The only worlds I've planned out are this one, the last one (which is extremely important to the main plot), and I have a general idea of the magic dimension.

**Anyways, thanks for reading, see you again in November.**


End file.
